ZF-25M delay before engaging

[chris95040]

Hi,

I have a ZF-25M (m= mechanically actuated disc clutches).

My engine, a westerbeke 55b4, likes to idle at 1000RPM and this is where I normally shift from, but I’m noticing lately I need to wind down to 700rpm or so to avoid a long (3-5 seconds) delay between putting it in drive and hearing it ‘clunk’ into gear.

Anyone have any ideas? BTW its a fairly new tranny.

[tkeithlu]

Have you checked the transmission fluid? A delay in engaging is often a sign of the tranny having to pump up some fluid. But, that doesn't really match with your observation that it shifts quickly at low RPM and not at 1,000.

Oh. Could you have a cable problem? It may take more pressure from the cable (they all have some variation as they push against the sheath) to shift with more load on the gears. Is it in adjustment, or wearing?